Officials are concerned that a sinkhole in western Pennsylvania is now more dangerous and unstable after a missing woman reportedly fell through it while babysitting her granddaughter.

Heavy machinery and sound-monitoring equipment are being used in the search for a Pennsylvania grandmother who is believed to have fallen through a sinkhole deep into fragile, unstable ground while searching Monday for her cat,

Rescue workers remain optimistic as the search for a missing woman, who likely fell through a sinkhole while searching for her runaway cat, continues at an abandoned mine in Westmoreland County, Pennsylvania,